Search results
Results from the WOW.Com Content Network
In toxicology, the median lethal dose, LD 50 (abbreviation for "lethal dose, 50%"), LC 50 (lethal concentration, 50%) or LCt 50 is a toxic unit that measures the lethal dose of a given substance. [1] The value of LD 50 for a substance is the dose required to kill half the members of a tested population after a specified test duration.
The median effective dose is the dose that produces a quantal effect (all or nothing) in 50% of the population that takes it (median referring to the 50% population base). [6] It is also sometimes abbreviated as the ED 50, meaning "effective dose for 50% of the population". The ED50 is commonly used as a measure of the reasonable expectancy of ...
The median lethal dose, LD 50 (abbreviation for "lethal dose, 50%"), LC 50 (lethal concentration, 50%) or LCt 50 (lethal concentration and time) of a toxin, radiation, or pathogen is the dose required to kill half the members of a tested population after a specified test duration.
Water intoxication can be prevented if a person's intake of water does not grossly exceed their losses. Healthy kidneys can excrete approximately 800 millilitres to one litre of fluid water (0.84–1.04 quarts) per hour. [15] However, stress (from prolonged physical exertion), as well as disease states, can greatly reduce this amount. [15]
The dose values are divided by the maximum dose, referred to as d max, yielding a plot in terms of percentage of the maximum dose. Dose measurements are generally made in water or "water equivalent" plastic with an ionization chamber , since water is very similar to human tissue with regard to radiation scattering and absorption.
A container with cream. Topical cream formulation is an emulsion semisolid dosage form that is used for skin external application. Most of the topical cream formulations contain more than 20 per cent of water and volatiles and/or less than 50 per cent of hydrocarbons, waxes, or polyethylene glycols as the vehicle for external skin application. [1]
Note that LD 50 means lethal dose, 50 percent kill; LDLo means lowest published lethal dose; TDLo means lowest published toxic dose; For humans the lowest published oral lethal dose of 28 μg/kg was reported in 1969.
A reference dose is the United States Environmental Protection Agency's maximum acceptable oral dose of a toxic substance, "below which no adverse noncancer health effects should result from a lifetime of exposure". Reference doses have been most commonly determined for pesticides. The EPA defines an oral reference dose (abbreviated RfD) as: